Hi Hanlin, This is a finite system, so conductivity cannot become infinite, it can only scale with the system size. Moreover, the examples we have in the documentation show the system in the quantum Hall regime, which has a finite conductivity even in the infinite system size limit. Best, Anton On Wed, 29 Dec 2021 at 14:52, <674657065@qq.com> wrote:

Dear all： I am a PHD student and i am using the kwant to calculate the conductivity of the graphene. Excuse me, I'd like to ask you a question that in the kwant documentation, you used the KPM method to calculate the conductivity of graphene. Does the disorder strength take a value of 0 or approach 0? If the disorder strength is 0, why is the conductivity not diverging at points where the energy is not zero? Thank you for your answer. Best wishes

Hanlin Liu